What term is used for an amino acid chain that has greater than 50 covalently linked amino acids?

• A. Protein.
• B. Peptide.
• C. Amino acid.
• D. Polypeptide.

Answer: (D)

Verified step by step guidance

1. Begin by understanding the basic structure of amino acids and how they link together. Amino acids are organic compounds that combine to form proteins. They are linked by peptide bonds, which are covalent bonds formed between the carboxyl group of one amino acid and the amino group of another.
2. Recognize the terminology used to describe chains of amino acids. A chain of amino acids linked by peptide bonds is generally referred to as a peptide. Peptides can vary in length, and their classification changes based on the number of amino acids present.
3. Learn the distinction between peptides and polypeptides. A peptide typically refers to a short chain of amino acids, usually fewer than 50. When the chain exceeds 50 amino acids, it is commonly referred to as a polypeptide.
4. Understand that proteins are composed of one or more polypeptides. Proteins are large, complex molecules that play many critical roles in the body. They are made up of one or more polypeptide chains that fold into a specific three-dimensional shape.
5. Conclude that the term used for an amino acid chain with greater than 50 covalently linked amino acids is 'polypeptide'. This term is used to describe the longer chains that are often precursors to functional proteins.